Safety latch for hoist hook

ABSTRACT

A safety latch for a crane hook includes arm sections which are attached for movement to a shank of the hook adjacent to the mouth of the hook. Each arm has a spring biased pin which engages and seats in a related opening formed in the tip of the hook which facilitates the locking of the latch across the mouth of the hook after a load has been attached to the hook. Also, at the end of each arm section there is provided a notch which supports the enlarged point of the hook and prevents the point of the hook from catching in other objects. This notch keeps the point of the hook from bending outwardly under an extreme overload.

[ 1 Aug. 6, 1974 SAFETY LATCH FOR HOIST HOOK [76] Inventor: Lewis C. Byers, 3 Fairfield Dr.,

Baltimore, Md. 21228 [22] I Filed: Jan. 5, 1973 [21] Appl. No.: 321,241

[52] US. Cl 294/82 R, 24/241 PP, 24/241 SB 804,454 11/1958 Great Britain 294/82 R Primary ExaminerEvon C. Blunk Assistant Examiner-Johnny D. Cherry Attorney, Agent, or FirmWalter G. Finch [5 7] ABSTRACT A safety latch for a crane hook includes arm sections which are attached for movement to a shank of the hook adjacent to the mouth of the hook. Each arm has a spring biased pin which engages and seats in a related opening formed in the tip of the hook which facilitates the locking of the latch across the mouth of the hook after a load has been attached to the hook. Also, at the end of each arm section there is provided a notch which supports the enlarged point of the hook and prevents the point of the hook from catching in other objects. This notch keeps the point of the hook from bending outwardly under an extreme overload.

12 Claims, 6 Drawing Figures PATENTED AUG 1974 SHEET 1 [1F 2 PATENTEU AUG 51974 sum 2 or 2 SAFETY LATCH FOR HOIST HOOK This invention relates to a safety latch for a hoist hook and more particularly pertains to a. safety latch which is lockable across the mouth of a crane hook after a load has been placed on the hook.

Many different types of hook-mouth latches are available forpositioning across the mouth of a hook for safety purposes. Usually, these latches depend on structure contained with the latch which is secured to the shank of the hook for locking the latch in place.

A latch which is securable at both sides of the mouth of the hook would insure thelocking of the latch to the hook. Also, concealment of unlatching facilities would preclude accidental unlocking of the latch.

It is, therefore, an object of this invention to provide a safety latch for a hoist hook securable at both ends across the mouth of the hook.

Another object of this invention is to provide a safety latch for a hoist hook with releasable locking facilities being concealed from accidental unlocking of the safety latch.

Another object of this invention is to provide a safety latch in which each arm section is prevented from being deflected inwardly and which also protects the point of a hook from catching in other objects.

Still anotherobject of this invention is to provide a safety latch for positioning across the mouth of a hoist hook with spring biased locking facilities for holding the latch in place.

Other objects and attendant advantages of this invention will become more readily apparent and understood from the following detailed specification and accompanying drawings in which:

FIG. 1 is a side elevation view of a pivotable embodiment of an inventive safety latch for a hoist hook;

FIG. 2 is a front elevation view of the safety latch of FIG. 1;

FIG. 3 is a partial top view of releasable locking facilities of the safety latch of FIG. 1;

FIG. 4 is a side elevation view of a hinged embodiment of the inventive safety latch for a hoist hook;

FIG. 5 is a front elevation view of the safety latch of FIG. 4; and

FIG. 6 is a partial top view of releasable locking facilities of the safety latch of FIG. 4.

A pivotally mounted latch 10 (FIG. 1) and hinged latch 12 (FIG. 4) illustrate two embodiments of a safety latch which is attachable to a hook 14.

As illustrated in FIG. 1, the hook 14 is formed with an attaching ring 16. The safety latch 10 includes an arm 18 which is formed with a yoke at one end to facilitate the pivotal securing of the arm to the shank of the book 14 by a pin 20.

As more clearly illustrated in FIGS. 2 and 3, the other end of the arm 18 is also formed with a yoke which is unsecured. The spaced sections of the yoked end of the arm 18 are formed with complimentary structure, such as openings, to receive the tip ends of securing pins 22. The other end of each of the pins 22 is formed with a reduced section which fits into a slot '(FIG. 1) formed in one leg of an associated one of a pair of L-shaped actuating levers 24. The other leg of each of the levers 24 extends inwardly through the spaced sections of the unsecured end of the arm 18.

The inwardly extended leg of each of the levers 24 provide pressure release points 26 (FIG. 3) which are normally urged toward the secured end of the arm 18 by an associated spring 28. This is further facilitated by the mounting of the levers 24 for movement to mounting brackets 30. As the springs 28 urge the inwardly extended leg of each of the levers toward the secured end of the arm 18, the other leg moves the associated pin 22 inwardly. This is the normal position maintained by the pins 22.

In an unlocked condition, the arm 18 is free to pivot from the phantom position illustrated in FIG. 1 to the full view locked position. As the arm 18 is moved toward the locked position by spring on FIGS. 1 and 2, or spring 62 in FIG. 4, the inwardly directed ends of the pins 22 engage the hook 14 near the free end thereof which forms one side of the mouth of the hook. This causes the pins 22 to be moved outwardly against the biasing force of the springs 28 until the pins are aligned with openings 32 which are illustrated in dashed lines in FIG. 2.

As the pins 22 are aligned with the openings 32, the pins move into the openings to lock the arm 18 in the position illustrated in full view in FIGS. 1 and 2. In addition, the tip end of the hook opening is formed with an enlargement 34. The enlargement 34 forms a pair of shoulders on opposite undersides thereof which further serve to preclude movement of the arm 18 beyond the full-view, locked position illustrated in FIG. 1.

In FIG. 1 and FIG. 2 the underside of the enlargement 34 slopes upwardly away from its edge and thus prevents the notched end of each arm section from spreading apart.

Thus the latch 10 has the self-contained securing pins 22 which faciltiate the locking of the arm 18 of the latch across the mouth of the hook 14. The enlargement 34 further facilitates the preclusion of movement of the arm 18 beyond the mouth of the hook 14 and the locked position. The releasing facilities, which include the pressure release points 26 of the levers 24, are contained inwardly of the spaced sections of the arm 18 to preclude accidental release of the locking facilities. Thus the latch 10 is selectively releasable when in the locked condition.

Although the arm 18 is illustrated as including two spaced parallel sections linked by an integrally formed web, the sections could be separate, unlinked arms independently controlled without departing from the scope of the invention.

The hinged latch 12 (FIG. 4) includes a pair of arms 40, as illustrated in FIGS. 4, 5 and 6. Each of the arms 40 are mounted by a hinge 42 to the shank of the hook 14 adjacent to the mouth thereof. A locking mechanism 44 for the hinged arms 40 includes a fixed arm 46 extending inwardly of and secured to one of the arms 40 and having an upwardly turned end as particularly illustrated in FIG. 6. The locking mechanism 44 further includes a movable arm 48, with a pressure release tab 50, which is mounted for pivoting movement by a pinmounting 52 to the other arm 40. The arm 48 also extends'inwardly of its arm 40 and has a downwardly turned end, as illustrated in FIG. 6, which is normally urged into this position by a spring 56 (FIG. 5).

When the hinged arms 40 are moved toward each other, bevelled surfaces of the turned ends of the arms 46 and 48 engage. The movable arm 48 is pivoted against the biasing action of the spring 56 until its turned end clears the turned end of the arm 46. Thereafter the spring 56 causes the arm 48 to snap into the locking position illustrated in FIG. 6. ln order to release the locking mechanism 44, pressure is applied to the tab 50 in the direction of the arrow (FIG. 6) whereby the arm 48 is pivoted away from and clear of the arm 46. The hinged arms 40 can then be moved apart.

Each arm 40 has a securing pin 54 mounted at the unsecured end thereof and extending inwardly of the arm. When the arms 40 are moved toward each other, the inward ends of the arms project into the openings 32 (FIG. formed in the hook 14 near the tip end thereof. This facilitates the positioning of the arms 40 across the mouth of the hook 14 and the locking mechanism 44 locks the latch 12 in place thereby closing the mouth.

The locking mechanism 44 is concealed between the arms 40 which precludes release of the latch 12 by an accidental force. Thus, the locked latch 12 is selectively releasable.

The enlargement 34 of the hook 14 forms shoulders which preclude movement of the arms 40 in a plane parallel with the hook and outwardly of the mouth thereof.

With respect to the latch 10 and the latch 12, the enlargement 34 precludes movement of the arm 18 and arms 40, respectively, as previously explained. This feature permits movement of the load positioned within the hook opening without concern for the moving load from forcing the latches l0 and 12 outwardly from the locked position. For example, assume that a cable load is looped within the opening of the hook l4 and the latch 10 or 12 is locked across the mouth of the hook. If the load is moved against the latch 10 or 12 during manipulation of the hook 14 and the load, the latch is precluded from moving outwardly from the mouth of the hook. This is not only accomplished by the locking action of the securing pins 32 and associated locking mechanisms but also by the abutting of the ends of the arm 18 and the arms 40 against the shoulders of the enlargement 34.

Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

l. A safety latch for a hoist hook having a shank and a tip spaced apart therefrom by the mouth of the hook, comprising:

closing means secured at one end thereof to the shank of the hook for closing the mouth of the hook;

securing means attached to said closing means for engaging a complementary structure formed in the tip of said hook and securing the closing means across the mouth of the hook, the securing means comprising at least one pin mounted on said closing means and positioned for location within an associated opening formed in the tip of the hook and means for biasing said pin into said opening to secure said closing means across the mouth of the hook; and,

means for locking the securing means with the closing means across the mouth of the hook to preclude a load within the hook from moving through the mouth of the hook.

2. A safety latch as recited in claim 1 wherein said closing means includes an arm pivotally mounted to the shank of the hook for pivotal movement into the closed position across the mouth of the hook.

3. A safety latch as recited in claim 1 wherein said closing means includes at least one arm hinged to the shank of the hook for swinging movement into the closed position across the mouthof the hook.

4. A safety latch as recited in claim 1 wherein said locking means includes,

a lever mounted for pivotal movement to said closing means and retaining said securing means in attachment to said closing means, and

' means for urging said lever into a position to lock said securing means so that the closing means is locked across the mouth of the hook.

5. A safety latch as recited in claim 1 wherein said closing means includes a pair of arms movable toward each other in a closed position across the mouth of the hook and said locking means includes,

a fixed arm attached to and extending from one arm of the closing means toward the other, said fixed arm formed with a turned end,

a movable arm attached for movement to the other arm of the closing means and having a turned end lockingly engageable with the turned end of said fixed arm when said pair of arms of said closing means are closed about the mouth of the hook, and

means for urging the movable arm into a normal position for locking engagement with the fixed arm.

6. A safety latch as recited in claim 1 which further comprises means for selectively releasing the locking means to permit movement of the closing means away from the mouth of the hook.

7. A safety latch as recited in claim 8 which further comprises means for concealing said releasing means to preclude accidental releasing of the locking means.

8. The safety latch of claim 1 and further comprising means independent of said securing means and said locking means and formed in the tip of the hook for precluding movement of said closing means outwardly from the mouth of the hook when said closing means closes the mouth thereof.

9. A safety latch as recited in claim 8 wherein said precluding means includes an enlargement formed in the tip of said hook which forms shoulders located to preclude movement of said closing means outwardly of the mouth of the hook while the closing means is in the closed position across the mouth of the hook.

10. A safety latch as recited in claim 8 wherein said precluding means includes an enlargement formed in the tip of said hook which forms shoulders having an underside sloping up from its edge to prevent spreading apart of unsecured closing means and is located to preclude movement of said closing means outwardly of the mouth of the hook while the closing means is in the closed position across the mouth of the hook.

11. A safety latch for a hoist hook having a shank and a tip spread apart therefrom by the mouth of the hook, comprising:

closing means secured at one end thereof to the shank of the hook for closing the mouth of the hook;

securing means attached to said closing means for engaging a complementary structure formed in the tip of said hook and securing the closing means across the mouth of the hook; and,

means for locking the securing means with the closing means across the mouth of the hook to preclude a load within the book from moving through the mouth of the hook, said locking means including a lever mounted for pivotal movement to said closing means and retaining said securing means in attachment to said closing means, and means for urging said lever into a position to lock said securing means so that the closing means is locked across the mouth of the hook. 12. A safety latch for a hoist hook having a shank and a tip spaced apart therefrom by the mouth of the hook comprising:

closing means secured at one end thereof to the shank of the hook for closing the mouth of the hook, said closing means including a pair of arms movable toward each other in a closed position across the mouth of the hook; securing means attached to said closing means for engaging a complementary structure formed in the tip of said hook and securing the closing means across the mouth of the hook; and,

means for locking the securing means with the closing means across the mouth of the hook to preclude a load within the hook from moving through the mouth of the hook, paid locking means including a fixed arm attached to and extending from one arm of the closing means toward the other, said fixed arm being formed with a turned end, a movable arm attached for movement to the other arm of the closing means and having a turned end lockingly engageable with the turned end of said fixed arm when said pair of arms of said closing means are closed about the mouth of the hook, and means for urging the movable arm into a normal position for locking engagement with the fixed arm. 

1. A safety latch for a hoist hook having a shank and a tip spaced apart therefrom by the mouth of the hook, comprising: closing means secured at one end thereof to the shank of the hook for closing the mouth of the hook; securing means attached to said closing means for engaging a complementary structure formed in the tip of said hook and securing the closing means across the mouth of the hook, the securing means comprising at least one pin mounted on said closing means and positioned for location within an associated opening formed in the tip of the hook and means for biasing said pin into said opening to secure said closing means across the mouth of the hook; and, means for locking the securing means with the closing means across the mouth of the hook to preclude a load within the hook from moving through the mouth of the hook.
 2. A safety latch as recited in claim 1 wherein said closing means includes an arm pivotally mounted to the shank of the hook for pivotal movement into the closed position across the mouth of the hook.
 3. A safety latch as recited in claim 1 wherein said closing means includes at least one arm hinged to the shank of the hook for swinging movement into the closed position across the mouth of the hook.
 4. A safety latch as recited in claim 1 wherein said locking means includes, a lever mounted for pivotal movement to said closing means and retaining said securing means in attachment to said closing means, and means for urging said lever into a position to lock said securing means so that the closing means is locked across the mouth of the hook.
 5. A safety latch as recited in claim 1 wherein said closing means includes a pair of arms movable toward each other in a closed position across the mouth of the hook and said locking means includes, a fixed arm attached to and extending from one arm of the clOsing means toward the other, said fixed arm formed with a turned end, a movable arm attached for movement to the other arm of the closing means and having a turned end lockingly engageable with the turned end of said fixed arm when said pair of arms of said closing means are closed about the mouth of the hook, and means for urging the movable arm into a normal position for locking engagement with the fixed arm.
 6. A safety latch as recited in claim 1 which further comprises means for selectively releasing the locking means to permit movement of the closing means away from the mouth of the hook.
 7. A safety latch as recited in claim 8 which further comprises means for concealing said releasing means to preclude accidental releasing of the locking means.
 8. The safety latch of claim 1 and further comprising means independent of said securing means and said locking means and formed in the tip of the hook for precluding movement of said closing means outwardly from the mouth of the hook when said closing means closes the mouth thereof.
 9. A safety latch as recited in claim 8 wherein said precluding means includes an enlargement formed in the tip of said hook which forms shoulders located to preclude movement of said closing means outwardly of the mouth of the hook while the closing means is in the closed position across the mouth of the hook.
 10. A safety latch as recited in claim 8 wherein said precluding means includes an enlargement formed in the tip of said hook which forms shoulders having an underside sloping up from its edge to prevent spreading apart of unsecured closing means and is located to preclude movement of said closing means outwardly of the mouth of the hook while the closing means is in the closed position across the mouth of the hook.
 11. A safety latch for a hoist hook having a shank and a tip spread apart therefrom by the mouth of the hook, comprising: closing means secured at one end thereof to the shank of the hook for closing the mouth of the hook; securing means attached to said closing means for engaging a complementary structure formed in the tip of said hook and securing the closing means across the mouth of the hook; and, means for locking the securing means with the closing means across the mouth of the hook to preclude a load within the hook from moving through the mouth of the hook, said locking means including a lever mounted for pivotal movement to said closing means and retaining said securing means in attachment to said closing means, and means for urging said lever into a position to lock said securing means so that the closing means is locked across the mouth of the hook.
 12. A safety latch for a hoist hook having a shank and a tip spaced apart therefrom by the mouth of the hook comprising: closing means secured at one end thereof to the shank of the hook for closing the mouth of the hook, said closing means including a pair of arms movable toward each other in a closed position across the mouth of the hook; securing means attached to said closing means for engaging a complementary structure formed in the tip of said hook and securing the closing means across the mouth of the hook; and, means for locking the securing means with the closing means across the mouth of the hook to preclude a load within the hook from moving through the mouth of the hook, paid locking means including a fixed arm attached to and extending from one arm of the closing means toward the other, said fixed arm being formed with a turned end, a movable arm attached for movement to the other arm of the closing means and having a turned end lockingly engageable with the turned end of said fixed arm when said pair of arms of said closing means are closed about the mouth of the hook, and means for urging the movable arm into a normal position for locking engagement with the fixed arm. 